/* Global Styles */
:root {
    /* Light theme variables */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --light-bg: #f8f9fa;
    --dark-bg: #2c3e50;
    --card-bg: #ffffff;
    --border-color: #ddd;
    --shadow-color: rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --primary-color: #ecf0f1;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #ecf0f1;
    --light-bg: #1a1a1a;
    --dark-bg: #2c3e50;
    --card-bg: #2c3e50;
    --border-color: #34495e;
    --shadow-color: rgba(0,0,0,0.3);
    --text-muted: #bdc3c7;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--dark-bg);
    padding: 1rem 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    color: white;
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 2rem;
}

.nav-links a {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--secondary-color);
}

/* Hero Section */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(44, 62, 80, 0.9), rgba(44, 62, 80, 0.9)),
                url('../images/hero-bg.jpg') center/cover;
    display: flex;
    align-items: center;
    text-align: center;
    color: white;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.hero h2 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--secondary-color);
}

.tagline {
    font-size: 1.2rem;
    margin-top: 1rem;
    color: #ecf0f1;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s ease;
    margin: 0.5rem;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-secondary {
    background-color: transparent;
    color: white;
    border: 2px solid white;
}

/* Update the light theme styles with higher specificity */
body[data-theme="light"] .btn-secondary,
[data-theme="light"] .btn-secondary {
    color: var(--primary-color);
    border-color: var(--primary-color);
}

/* Ensure hero section buttons are always visible */
.hero .btn-secondary {
    color: white;
    border-color: white;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

/* Page Header */
.page-header {
    background-color: var(--dark-bg);
    color: white;
    padding: 8rem 0 4rem;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

/* Featured Grid */
.featured-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.featured-item {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.featured-item:hover {
    transform: translateY(-5px);
}

.featured-item i {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

/* Sections */
.section {
    padding: 5rem 0;
}

.section:nth-child(even) {
    background-color: var(--light-bg);
}

.section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
    font-size: 2.5rem;
}

/* Research Grid */
.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.research-item {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.research-item:hover {
    transform: translateY(-5px);
}

.research-item i {
    font-size: 2.5rem;
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

/* Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

.timeline-item h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.institution {
    color: var(--secondary-color);
    font-weight: bold;
}

.period {
    color: #666;
    font-style: italic;
}

.description {
    margin-top: 1rem;
    color: #666;
}

/* About Content */
.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text h2 {
    margin: 2rem 0 1rem;
    color: var(--primary-color);
}

/* Interests Grid */
.interests-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.interest-item {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    text-align: center;
}

.interest-item i {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 1rem;
}

/* Contact Section */
.contact-info {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-info p {
    margin: 1rem 0;
}

.contact-info a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.contact-info a:hover {
    color: var(--accent-color);
}

/* Footer */
footer {
    background-color: var(--dark-bg);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Projects Grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background: var(--card-bg);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 3px 10px var(--shadow-color);
    transition: transform 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
}

.project-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-content {
    padding: 1.5rem;
}

.project-content h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.project-category {
    color: var(--secondary-color);
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.project-description {
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.project-tags span {
    background-color: var(--light-bg);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.9rem;
    color: var(--primary-color);
}

/* Gallery Filters */
.gallery-filters {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1.5rem;
    border: none;
    background: var(--light-bg);
    color: var(--primary-color);
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--secondary-color);
    color: white;
}

/* Gallery Grid */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    padding: 1rem;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: 10px;
    aspect-ratio: 1;
    cursor: pointer;
    box-shadow: 0 3px 10px var(--shadow-color);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.gallery-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(0,0,0,0.8));
    color: white;
    padding: 1rem;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.gallery-item:hover .gallery-overlay {
    transform: translateY(0);
}

.gallery-overlay h3 {
    margin: 0;
    font-size: 1.2rem;
}

.gallery-overlay p {
    margin: 0.5rem 0 0;
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Lightbox */
.lightbox {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.9);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.lightbox.active {
    display: flex;
}

.lightbox-image {
    max-width: 90%;
    max-height: 90vh;
    object-fit: contain;
}

.close-lightbox {
    position: absolute;
    top: 20px;
    right: 30px;
    color: white;
    font-size: 2rem;
    cursor: pointer;
}

.lightbox-prev,
.lightbox-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    padding: 1rem;
}

.lightbox-prev {
    left: 20px;
}

.lightbox-next {
    right: 20px;
}

/* CV Styles */
.cv-content {
    max-width: 900px;
    margin: 0 auto;
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 3px 10px var(--shadow-color);
}

.cv-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--light-bg);
}

.cv-contact {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.cv-contact p {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.cv-contact i {
    color: var(--secondary-color);
}

.cv-section {
    margin-bottom: 2rem;
}

.cv-section h2 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--light-bg);
}

.cv-item {
    margin-bottom: 1.5rem;
}

.cv-item-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
}

.cv-item-header h3 {
    color: var(--primary-color);
    margin: 0;
}

.cv-date {
    color: var(--secondary-color);
    font-weight: bold;
}

.cv-institution {
    color: var(--secondary-color);
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.cv-description {
    color: var(--text-muted);
}

.cv-list {
    list-style: none;
    padding-left: 1.5rem;
    margin-top: 0.5rem;
}

.cv-list li {
    position: relative;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

.cv-list li::before {
    content: "•";
    color: var(--secondary-color);
    position: absolute;
    left: -1.5rem;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.skill-category h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.cv-publication {
    margin-bottom: 1rem;
    line-height: 1.6;
}

/* Blog Styles */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.blog-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.blog-card:hover {
    transform: translateY(-5px);
}

.blog-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
}

.blog-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.blog-card:hover .blog-image img {
    transform: scale(1.05);
}

.blog-content {
    padding: 1.5rem;
}

.blog-meta {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.9rem;
    color: #666;
}

.blog-date {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.blog-category {
    color: var(--secondary-color);
    font-weight: bold;
}

.blog-content h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.blog-content p {
    color: #666;
    margin-bottom: 1.5rem;
}

/* Blog Pagination */
.blog-pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 3rem;
}

.page-numbers {
    display: flex;
    gap: 0.5rem;
}

.page-numbers a {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 5px;
    background: var(--light-bg);
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
}

.page-numbers a.active,
.page-numbers a:hover {
    background: var(--secondary-color);
    color: white;
}

/* Newsletter Signup */
.newsletter-signup {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
    padding: 3rem;
    background: white;
    border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

.newsletter-signup h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.newsletter-signup p {
    color: #666;
    margin-bottom: 2rem;
}

.newsletter-form {
    display: flex;
    gap: 1rem;
    max-width: 500px;
    margin: 0 auto;
}

.newsletter-form input {
    flex: 1;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

.newsletter-form input:focus {
    outline: none;
    border-color: var(--secondary-color);
}

/* Theme Toggle Button */
.theme-toggle {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0.5rem;
    margin-left: 1rem;
    transition: transform 0.3s ease;
}

.theme-toggle:hover {
    transform: rotate(180deg);
}

/* Mobile Navigation */
.mobile-nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
}

@media (max-width: 768px) {
    .mobile-nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--dark-bg);
        flex-direction: column;
        padding: 1rem 0;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        margin: 0.5rem 0;
        text-align: center;
    }

    .profile-section {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
        padding: 1rem;
    }

    .profile-image {
        flex: 0 0 200px;
        height: 200px;
    }

    .profile-text h1 {
        font-size: 2rem;
    }

    .profile-text .affiliation {
        font-size: 1rem;
    }

    .profile-text .bio {
        font-size: 1rem;
    }

    .profile-buttons {
        flex-direction: column;
        gap: 1rem;
    }

    .profile-buttons .btn {
        width: 100%;
        text-align: center;
    }

    .gallery-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 1rem;
    }

    .category-btn {
        padding: 0.4rem 1rem;
        font-size: 0.9rem;
    }

    .lightbox-image {
        max-width: 95%;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .blog-grid {
        grid-template-columns: 1fr;
    }

    .cv-content {
        padding: 1rem;
    }

    .cv-header {
        flex-direction: column;
        gap: 1rem;
    }

    .cv-contact {
        grid-template-columns: 1fr;
    }

    .cv-item-header {
        flex-direction: column;
        gap: 0.5rem;
    }

    .cv-date {
        margin-left: 0;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }
}

/* Home Page Layout */
.home-content {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 6rem 0;
    background-color: var(--light-bg);
}

.profile-section {
    display: flex;
    align-items: center;
    gap: 4rem;
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 15px;
    box-shadow: 0 5px 20px var(--shadow-color);
}

.profile-image {
    flex: 0 0 300px;
    height: 300px;
    border-radius: 50%;
    overflow: hidden;
    border: 5px solid var(--secondary-color);
}

.profile-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.profile-text {
    flex: 1;
}

.profile-text h1 {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.profile-text .affiliation {
    font-size: 1.2rem;
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
}

.profile-text .bio {
    font-size: 1.1rem;
    line-height: 1.6;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

[data-theme="dark"] .profile-text .bio {
    color: #ecf0f1;
}

.profile-buttons {
    display: flex;
    gap: 1rem;
}

.profile-buttons .btn {
    margin: 0;
}

@media (max-width: 768px) {
    .profile-section {
        flex-direction: column;
        text-align: center;
        gap: 2rem;
    }

    .profile-image {
        flex: 0 0 250px;
        height: 250px;
    }

    .profile-buttons {
        justify-content: center;
    }
}

.cv-link {
    display: inline-block;
    margin-top: 0.5rem;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.cv-link:hover {
    color: var(--accent-color);
}

.social-links {
    margin-top: 1rem;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: white;
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

.social-link:hover {
    color: var(--secondary-color);
}

.social-link i {
    font-size: 1.3rem;
}

.project-description {
    color: var(--text-muted);
}

[data-theme="dark"] .project-description {
    color: #ecf0f1;
}

.cv-description {
    color: var(--text-muted);
}

[data-theme="dark"] .cv-description {
    color: #ecf0f1;
}

.cv-list li {
    position: relative;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

[data-theme="dark"] .cv-list li {
    color: #ecf0f1;
}

[data-theme="dark"] .project-tags span {
    background-color: var(--dark-bg);
    color: var(--primary-color);
}

.social-icons {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

.social-icon {
    color: var(--secondary-color);
    font-size: 1.5rem;
    transition: all 0.3s ease;
}

.social-icon:hover {
    color: var(--accent-color);
    transform: translateY(-2px);
}

/* Photo Categories */
.photo-categories {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.category-btn {
    padding: 0.5rem 1.5rem;
    border: none;
    border-radius: 25px;
    background: var(--card-bg);
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
    box-shadow: 0 2px 5px var(--shadow-color);
}

.category-btn:hover {
    background: var(--secondary-color);
    color: white;
}

.category-btn.active {
    background: var(--secondary-color);
    color: white;
}